Soft actuators with tapered or skewed structures

Abstract

Exemplary embodiments relate to improvements in robotic systems to reduce biological or chemical harborage points on the systems. For example, in exemplary embodiments, robotic actuators, hubs, or entire robotic systems may be configured to allow crevices along joints or near fasteners to be reduced or eliminated, hard corners to be replaced with rounded edges, certain components or harborage points to be eliminated, shapes to be reconfigured to be smoother or flat, and/or or surfaces to be reconfigurable for simpler cleaning.

The invention claimed is: 
     
       1. A soft actuator comprising:
 an elastomeric body that extends from a proximal end to a distal end, the elastomeric body:
 surrounding a void configured to receive an inflation fluid, 
 comprising a plurality of accordion extensions, and 
 having first and second substantially straight sides that define a breadth of the elastomeric body and third and fourth substantially straight sides that define a thickness direction, the first, second, third, and fourth substantially straight sides extending a length of the elastomeric body and being tapered from the proximal end to the distal end in the breadth direction and the thickness direction, 
 
 the elastomeric body being substantially trapezoidal in cross-section. 
 
     
     
       2. The soft actuator of  claim 1 , wherein the soft actuator comprises a gripping surface on a base of the soft actuator, the gripping surface configured to extend to create a textured surface on the base when the actuator is in an inflated state, and configured to retract to create a smooth surface when the actuator is not in an inflated state. 
     
     
       3. The soft actuator of  claim 2 , wherein the gripping surface is formed by an internal channel configured to receive inflation fluid independently of a remainder of the soft actuator. 
     
     
       4. The soft actuator of  claim 2 , further comprising a control system for applying a predetermined amount of vacuum to the soft actuator, the predetermined amount corresponding to at least one of a configuration of a target object to be grasped or an environment in which the target object is located. 
     
     
       5. The soft actuator of  claim 1 , wherein the elastomeric body tapers to different degrees along the width of the actuator to alter lateral actuator stability as compared to an untapered actuator. 
     
     
       6. The soft actuator of  claim 1 , wherein the elastomeric body tapers to different degrees along the length of the actuator to alter axial stability as compared to an untapered actuator. 
     
     
       7. The soft actuator of  claim 1 , wherein a wall thickness of elastomeric body tapers to different degrees to alter a gradient change in expansion upon actuation as compared to an untapered actuator. 
     
     
       8. The soft actuator of  claim 1 , wherein amplitudes of respective accordion extensions exhibit different amplitudes, resulting in a gradient change in curvature response when compared to an untampered actuator. 
     
     
       9. A soft actuator comprising:
 an elastomeric body that has a substantially oval shape that extends along a major axis from a proximal end to a distal end and a minor axis extending in an axial direction of the soft actuator, the elastomeric body:
 surrounding a plurality of teardrop-shaped internal chambers configured to receive an inflation fluid, 
 comprising a plurality of accordion extensions, and 
 configured to bend along the major axis and the minor axis when inflated to create a cupping shape. 
 
 
     
     
       10. The soft actuator of  claim 9 , wherein the elastomeric body is tapered in a thickness direction from the proximal end to the distal end. 
     
     
       11. The soft actuator of  claim 9 , further comprising a central opening extending through the actuator in a thickness direction. 
     
     
       12. The soft actuator of  claim 9 , wherein the teardrop-shaped internal chambers include a relatively narrow region that expands into a relatively wider region. 
     
     
       13. The soft actuator of  claim 12 , wherein the relatively narrow region is disposed closer to a center of the actuator as compared to the relatively wider region. 
     
     
       14. A robotic gripper comprising a plurality of the soft robotic actuators of  claim 9  arranged in a circular or rectangular arrangement and configured to fully enclose a target object when inflated, the soft robotic actuators having a predetermined breadth selected to for an enveloping sphere when the soft robotic actuators are inflated with the inflation fluid.